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Saturday, 31 October

JEE Main · Chemistry · The p-Block Elements

Isostructural and Isoelectronic Identification

JEE Main asked Isostructural and Isoelectronic Identification 2 times in 2 of the 108 shifts Lumi analysed, in 2021 and 2026. It belongs to VSEPR Theory, in The p-Block Elements (Chemistry). The longest wait between two years asking it was 5 years.

Updated 2026-10-24

Times asked
2
in 2 shifts
Years
2 of 8
First asked
2021
last in 2026
Pattern
Occasional
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2021 and 2026. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.10.20’170’200.03’210’220’230’240’250.11’26

Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 1 in 24 shifts · 2022: 0 in 24 shifts · 2023: 0 in 12 shifts · 2024: 0 in 18 shifts · 2025: 0 in 8 shifts · 2026: 1 in 9 shifts.

Shift by shift

Each square is one analysed shift, in date order. Open a filled one for that paper.

  • 20261 of 9
  • 20250 of 8
  • 20240 of 18
  • 20230 of 12
  • 20220 of 24
  • 20211 of 24
  • 20200 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Single correct is the usual form. Skill tested: application.

  • Identify isostructural species
  • Identify isostructural species pairs

Difficulty

Easy 0Medium 2Hard 0

Every question was multiple choice.

Every question

All 2 questions

From the official JEE Main shift papers, newest first. Open one for the full question, the options and the official answer.

  1. 2 Apr 2026, Shift 2 · Q53SF4SF_4 is isostructural with: A. BrF4⊕BrF_4^{\oplus} B. CH4CH_4 C. IF4⊕IF_4^{\oplus} D. XeF4XeF_4 E. XeO2F2XeO_2F_2 Choose the correct answer from the…MediumSingle correct
  2. 24 Feb 2021, Shift 1 · Q31Which of the following are isostructural pairs ? A. SO42−\mathrm{SO_4^{2-}} and CrO42−\mathrm{CrO_4^{2-}} B. SiCl4\mathrm{SiCl_4} and…MediumSingle correct

Shifts: 24 Feb 2021, Shift 1, 2 Apr 2026, Shift 2.

Same topic

Other ideas in VSEPR Theory

VSEPR Theory has 25 ideas JEE Main has asked; 13 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisAll repeated ideas